The present invention relates to a video signal selecting device for use with a video apparatus, a television receiver or the like, in which a plurality of external input terminals are provided, the video signal selecting device being capable of selecting a desired video signal from among video signals applied thereto in accordance with an instruction externally applied.
The video apparatus is provided with external input terminals, that is, a video input terminal and an antenna input terminal. Selection of those input terminals is externally made by use of a remote control unit. An external input switching device disposed in a video apparatus, which corresponds to the video signal selecting device, is known as disclosed in U.S. Pat. No. 4,405,946, for example.
In the disclosed video apparatus, an instruction to select or designate a desired broadcasting wave arriving at the antenna input terminal is generated by use of a remote control unit; the broadcasting signal of the selected channel is input to the video apparatus; and a character of a channel number is displayed, in a superimposing fashion, on the screen of a television receiver (TV set) coupled to the antenna output terminal of the video apparatus. When the television signal of the selected channel is not input to the video apparatus, such a superimposing display is not performed.
In the disclosed video apparatus, the channel number is displayed in a superimposing fashion on the display screen. In some contents of display, the channel number displayed is illegible. Furthermore, when the television signal of the selected channel is not input to the video apparatus, the superimposing display is not presented as described the above. Therefore, the user cannot recognize whether or not the channel select is actually made. In this respect, the handling of the video apparatus is not good. There are many forms of television broadcastings, for example, general television broadcasting, satellite television broadcasting, and cable television broadcasting. The number of external input terminals of the video apparatus will be increased in the future. In this respect, the problems mentioned above will be serious.
It is therefore an object of the present invention is to provide a video signal selected device which makes it easy to recognize a selecting operation for the input external signals.
In order to achieve the above object, there is provided a video signal selecting device for selectively outputting one of a plurality of input video signals to a video display apparatus in accordance with an instruction input, the selecting device comprising: a selector for selectively outputting one signal of the plural video signals; an OSD (On Screen Display) control section for displaying symbol information on uniformly colored background indicating that the selective output is executed on a screen of the video display apparatus; and a control circuit section for controlling the selective output of the selector in accordance with the instruction input, and for detecting a change of the instruction input to start up the OSD control section.
In the thus arranged video signal selecting device, when the current instruction is changed to another instruction, the control circuit section issues a command to the related portions of the device. In response to the command, the OSD control section operates and causes a video display apparatus coupled to an output terminal to which a selected video signal is to be transmitted to display, for example, characters which indicate that the current instruction has been changed to another instruction, on the uniformly colored back-screen of the video display apparatus. At the same time, the selector selects another video signal in accordance with the new instruction, and allows the selected video signal to pass therethrough and reach the output terminal.
Specifically, when another or new instruction is issued in place of the old one, a character chain representative of a change of instruction is displayed on the uniformly colored back-screen, and then the display of the characters is shifted to a display of an image defined by the video signal. Every time the instruction is changed to another, a character chain representative of a change of the instruction is displayed on the back-screen. Therefore, the user can easily know the change of instruction from the display.
The video signal selecting device may further comprises a sync signal separator for separating a sync signal included in each of the video signals, wherein the control circuit section halts the OSD control section when the sync signal is output from the sync signal separator. The halting operation of the control circuit section may be executed after the sync signal output from the sync signal separator in predetermined interval.
In the video signal selecting device thus arranged, when the video signal as instructed passes through the selector and the sync signal separator separates a sync signal from the video signal, the operation of the OSD control section is halted and thereby the display of the characters indicating the instruction change is shifted to a display of an image defined by the video signal.
When the video signal as instructed is not input to the video signal selecting device, the display on the display screen remains unchanged. When seeing this, the user can recognize that no video signal reaches the video signal selecting device.
A color of the displayed symbol information may be different from the color of the displayed background. Thereby, the symbol information is distinguished and easy to read.
In order to achieve the above object, there may be provided a video signal selecting device for selectively outputting one of a plurality of input video signals to a video display apparatus in accordance with an instruction input, disposed in a video apparatus including an OSD control section, the selecting device comprising: a selector for selectively outputting one signal of the plural video signals; and a control circuit section for controlling the selective output of the selector in accordance with the instruction input, and for detecting a change of the instruction input to start up the OSD control section to display symbol information on uniformly colored background indicating that the selective output is executed on a screen of the video display apparatus.